The IARC Monographs on the Evaluation of Carcinogenic Risks to Humans is an international evidence-based approach to carcinogen hazard identification initiated in 1971. The overall objective is to identify preventable causes o cancer. This is advanced by conducting authoritative evaluations of suspected carcinogens and disseminating the results through multiple media. Because a broad range of exposures may contribute to human cancer, carcinogen evaluations encompass environmental and occupational exposures, physical and biological agents, chemicals, complex mixtures and lifestyle factors. Almost 1000 agents have been evaluated to date, with 114 classified as carcinogenic and 352 as probably or possibly carcinogenic to humans. Agents are selected for evaluation based on evidence of human exposure, suspicion of carcinogenicity, and public health importance. Each IARC Monograph includes systematic reviews of the pertinent scientific literature and an evaluation of the weight of the evidence that an agent or exposure may be carcinogenic to humans. Monographs are developed by Working Groups selected on the principles of including the best-qualified experts and avoiding conflicts of interest. Nationa and international health agencies use the IARC Monographs as a trustworthy source of scientific information and as the scientific basis for their efforts to control cancer. The specifc aims of this project are to: organize at least 10 Monograph meetings to evaluate candidate carcinogenic agents of high global relevance and concern; convene Working Groups that are scientifically rigorous, respected, and free of conflict of interest; enhance the systematic search evaluation and documentation of scientific data for carcinogen evaluations; advance the use of mechanistic data in carcinogen evaluations; promote wide dissemination of evaluation results and engage in collaborations with national and international organizations to improve the science and practice of evaluating potential carcinogens. Important new initiatives in the proposed project period are to: expand the spectrum of mechanistic data considered in making evaluations to additional data streams, such as high-throughput test results; further systematize the review of mechanistic data according to key characteristics of carcinogens; introduce new working procedures and Web-based tools to enhance the documentation of the search for and evaluation of relevant literature on cancer in humans, cancer in experimental animals, and relevant mechanisms.